This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The nuclear pore complex (NPC) is the largest protein assembly in eukaryotic cell, which mediate transport between nucleus and cytoplasm. NPC have approximately 30 unique proteins (known as nucleoporins), clustered together to form approximately 125 MDa protein complex in vertebrates. In spite of its important role in eukaryotic cell physiology, the structural details of NPC organization and its role in nuclear transport are not established yet. Structural studies on NPC are therefore important to elucidate the assembly of NPC and its role in various physiological processes such as mRNA export, viral entry into the nucleus, transport of cancer related factors etc. Our long-term goal is to reconstitute various sub complexes of vertebrate NPC and undertake crystallographic studies to determine high-resolution 3D structure.